The present invention relates generally to single point watering (SPW) systems. More particularly, the invention relates to an improved SPW system specially adapted for use with a particular class or style of lead-acid battery known in the art as a “deep cycle” battery.
Deep cycle batteries, widely used in boats and RVs, are ideal candidates for SPW maintenance. These batteries are commonly used to provide boats and RVs with “house power” for various accessories, including trolling motors, pumps, lighting and instruments. Deep cycle batteries are special 6 cell (12 volt) monoblocs, based on flooded, lead-acid technology, distinct from gel cell or absorbed glass mat technologies. Many boaters and RV owners prefer the flooded cell batteries to the alternatives. They have lower initial cost; they produce more amp hours of energy per pound; they use lower cost chargers; and they are more tolerant of overcharging. However, water is lost from the electrolyte in these batteries due to evaporation and electrolysis, and must be replaced periodically. As a result, a significant disadvantage of flooded cell batteries is that they require regular watering to maintain performance. This can be a significant problem. Batteries are frequently mounted in locations difficult to access, such as the bilge of a boat, or in small compartments that make it difficult to accurately add water manually. As a result, they often do not receive the regular watering they require, which can shorten batter life and weaken performance. If a practical SPW system were available for this class of batteries, it would prove valuable to a large number of boaters and RV owners.
Installing an SPW system on a deep cycle battery has heretofore been considered impractical. Cells are very closely spaced, and the battery cell vent openings are small in diameter, making individual SPW refill valves, designed for industrial use, too big and bulky to mount in deep cycle battery cells. With a cell spacing of 1 ⅝ in., there is not enough room to connect tubing to individual refill valves, even if they could fit into the small vent openings. In addition, multiple batteries are often used, with separate mounting arrangements and locations, making installation of an SPW system even more difficult, where control of water supply pressure, or residual water in the tubing could cause problems such as overfilling. A practical SPW system for this application would have to function reliably, independent of battery location and free of tightly controlled water supply pressure. Ideally, the vehicle operator could fill the batteries from a remote location, for example, in a boat while standing on the deck. The water should be supplied directly from a portable bottle of distilled water, or an easily accessed container of distilled water stored on the vehicle. Users will have a choice of water supply systems, such as a gravity fill or a small hand pump for a direct fill from a distilled water container, or a built-in electric pump, such as an inexpensive centrifugal pump, to provide push button battery watering.
What is needed, therefore, is an SPW system adapted particularly for use with the marine deep cycle class of lead-acid batteries.